1. Field of the Invention
This invention relates to a vacuum cleaner of the type for household use.
2. Description of the Prior Art
Water bath vacuum cleaners are well known and typically include a main vacuum with a removably attached water bath pan. An intake opening in the water bath pan matingly engages an inlet in the main housing of the vacuum cleaner to allow dust and dirt entrained air to be ingested by a vacuum force through the inlet into the area defined by the water bath pan. The primary advantage of the water bath filtering agent is that vacuum efficiency is not compromised as more dirt and dust is accumulated in the water bath. The dust and dirt are trapped in the water bath as the incoming air is directed into the water bath pan and circulated within. Traditional filtering media allow the flow of air through the filtering media to be impeded by the accumulation of the dirt and dust that has collected thereon. However, just as traditional filter media will allow very tiny microscopic particles to escape capture, the water bath and separator may also fail to capture all of the very small or microscopic particles that are light enough to remain suspended in the air as the air is circulated in the water bath pan.
High efficiency filters, or HEPA filters, are also widely used on vacuum cleaners in industrial and residential applications. These filters are made up of media with very tiny openings that are designed to capture the smallest microscopic particles that most traditional filtering media are incapable of capturing. The major drawback to the use of these types of filters is that due to the small size of the openings in the filter media, they capture all of the dirt and debris that hits them thereby clogging up very quickly, and requiring cleaning or replacement very often. For this reason, some vacuum cleaning products try to combine the HEPA filter with a more conventional dry filter media. The conventional dry filter media will capture the larger particles of dirt and debris, and the HEPA filter will only capture the smaller particles that escape the conventional dry filter media. The overall efficiency of the vacuum cleaner (and the conventional dry filter media) is affected as the air is redirected and routed through the additional filter. Also, the full area of the high efficiency filter is not utilized because the air is typically directed through a small opening in the main housing of the vacuum cleaner, which concentrates the flow of air on the portion of the high efficiency filter that is directly in front of the opening.